Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18;
MIME-Version: 1.0
References: <20210415135901.47131-1-andriy.shevchenko@linux.intel.com>
 <CAPcyv4jpkZNsQEvCe_dLoq0DOTrEX36vhkJg+zqEacUkJtvWiQ@mail.gmail.com>
 <CAHp75VcpQREYFesS9q2TeqrR29hf0CvMESM42AVGAFzEYeRr_Q@mail.gmail.com>
 <CAPcyv4jzg23CoQeqAyAR=PUjB4HG-FSnD8G0J7S=p22ANmzDMQ@mail.gmail.com> <YHnKg4MHkZ4QIBHR@smile.fi.intel.com>
In-Reply-To: <YHnKg4MHkZ4QIBHR@smile.fi.intel.com>
From:   Dan Williams <dan.j.williams@intel.com>
Date:   Fri, 16 Apr 2021 11:04:36 -0700
Message-ID: <CAPcyv4j+66FaPHPLkF+ZPQq=uncYJ1Mx8JMzZnhp86qS=JewjQ@mail.gmail.com>
Subject: Re: [PATCH v1 1/1] ACPI: NFIT: Import GUID before use
To:     Andy Shevchenko <andy.shevchenko@gmail.com>
Cc:     linux-nvdimm <linux-nvdimm@lists.01.org>,
        Linux ACPI <linux-acpi@vger.kernel.org>,
        Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
        Vishal Verma <vishal.l.verma@intel.com>,
        Dave Jiang <dave.jiang@intel.com>,
        Ira Weiny <ira.weiny@intel.com>,
        "Rafael J. Wysocki" <rjw@rjwysocki.net>,
        Len Brown <lenb@kernel.org>
Content-Type: text/plain; charset="UTF-8"
Precedence: bulk

On Fri, Apr 16, 2021 at 10:34 AM Andy Shevchenko
<andy.shevchenko@gmail.com> wrote:
>
> On Fri, Apr 16, 2021 at 09:15:34AM -0700, Dan Williams wrote:
> > On Fri, Apr 16, 2021 at 1:58 AM Andy Shevchenko
> > <andy.shevchenko@gmail.com> wrote:
> > > On Fri, Apr 16, 2021 at 8:28 AM Dan Williams <dan.j.williams@intel.com> wrote:
> > > > On Thu, Apr 15, 2021 at 6:59 AM Andy Shevchenko
> > > > <andriy.shevchenko@linux.intel.com> wrote:
> > > > >
> > > > > Strictly speaking the comparison between guid_t and raw buffer
> > > > > is not correct. Import GUID to variable of guid_t type and then
> > > > > compare.
> > > >
> > > > Hmm, what about something like the following instead, because it adds
> > > > safety. Any concerns about evaluating x twice in a macro should be
> > > > alleviated by the fact that ARRAY_SIZE() will fail the build if (x) is
> > > > not an array.
> > >
> > > ARRAY_SIZE doesn't check type.
> >
> > See __must_be_array.
> >
> > > I don't like hiding ugly casts like this.
> >
> > See PTR_ERR, ERR_PTR, ERR_CAST.
>
> It's special, i.e. error pointer case. We don't handle such here.
>
> > There's nothing broken about the way the code currently stands, so I'd
> > rather try to find something to move the implementation forward than
> > sideways.
>
> Submit a patch then. I rest my case b/c I consider that ugly castings worse
> than additional API call, although it's not ideal.

It sounds like you'll NAK that patch, and I'm not too enthusiastic
about these proposed changes either because I disagree that the code
is incorrect. Is there another compromise?